I used to be able to follow TV shows easily. I am just about to finish watching all 6 series of the Sopranos for the 5th time (will be my mastermind special subject if I ever get on the show). Easy to follow and ground-breakingly good dialogue and drama for its time.
TV shows nowadays are more sophisticated though and also more entertaining. But I can barely follow them. I just finished the sublime beyond words 'True Detective'. Loved every second but at the end of each episode I had to jump on Wikipedia and read the episode summary to explain what had actually happened. By episode 5 I started using the subtitles which helped me with the dialogue a bit but I still needed to check the plot details on the internet.
I had the same thing with early series of Game of Thrones (before I had a grip on all the characters) due to so many parallel story lines. Watched The Americans S02E01. Looks to be as good as season 1. But a couple of scenes I had to rewind and replay 4 times and then turn on subtitles to follow the dialogue. Just to obscure and fast. Same problem with House of Cards S02. Couldn't fully follow the plot-lines without checking internet but still top drawer TV with or without detailed plot understanding.
I suspect I would have enjoyed True Detective just as much if I had not bothered checking plot-line details as it was just so atmospheric and cleverly constructed and the character dynamic between Cohle and Hart was the most intense I have ever seen on a TV show. It also contained genuinely thought provoking philosophical comment.
Anyway I am not complaining since TV seems to have upped its game in the last few years and I don't mind having to get help to follow the plot when the production is so good.
There is also the possibility that TV shows are not getting more complicated and I am just getting more stupid.